Don't give back an egg when throwing it at another claim.

[Kronnixle]

Observed Behavior

Some plugins use unique items, and one of the items is an egg. Because the item is unique, the plugin handles dropping the item when it fails to hit another mob. However with Grief Prevention it also returns the egg back to the player, meaning there are now duplications of the same egg (causing an infinite cycle).

Expected Behavior

Either allow a configurable option to give players the egg back if they attempt to 'grief' by spawning mobs in another persons claimed land, or disable it entirely please.

Reproduction steps

Have eggs.
Throw them at a claimed land.
Get eggs back in your inventory.

Stack trace or error log

No response

Server version

This server is running Paper version git-Paper-84 (MC: 1.20.1) (Implementing API version 1.20.1-R0.1-SNAPSHOT) (Git: c016e03)

GriefPrevention version

GriefPrevention version 16.18.1

Configuration

# Default values are perfect for most servers.  If you want to customize and have a question, look for the answer here first: http://dev.bukkit.org/bukkit-plugins/grief-prevention/pages/setup-and-configuration/

GriefPrevention:
  SeaLevelOverrides:
    world: -1
    world_nether: -1
    world_the_end: -1
    void: -1
  Claims:
    Mode:
      void: Disabled
      world: Survival
      world_the_end: Disabled
      world_nether: Disabled
    PreventGlobalMonsterEggs: false
    PreventTheft: true
    ProtectCreatures: true
    PreventButtonsSwitches: false
    LockWoodenDoors: true
    LockTrapDoors: true
    LockFenceGates: true
    EnderPearlsRequireAccessTrust: false
    RaidTriggersRequireBuildTrust: true
    ProtectHorses: true
    ProtectDonkeys: true
    ProtectLlamas: true
    InitialBlocks: 1000
    Claim Blocks Accrued Per Hour:
      Default: 100
    Max Accrued Claim Blocks:
      Default: 100000
    Accrued Idle Threshold: 0
    AccruedIdlePercent: 0
    AbandonReturnRatio: 1.0
    AutomaticNewPlayerClaimsRadius: 5
    AutomaticNewPlayerClaimsRadiusMinimum: 0
    ExtendIntoGroundDistance: 5
    MinimumWidth: 5
    MinimumArea: 100
    MaximumDepth: -2147483648
    InvestigationTool: STICK
    ModificationTool: GOLDEN_SHOVEL
    Expiration:
      ChestClaimDays: 7
      UnusedClaimDays: 14
      AllClaims:
        DaysInactive: 60
        ExceptWhenOwnerHasTotalClaimBlocks: 10000
        ExceptWhenOwnerHasBonusClaimBlocks: 5000
      AutomaticNatureRestoration:
        SurvivalWorlds: false
    AllowTrappedInAdminClaims: false
    MaximumNumberOfClaimsPerPlayer: 0
    CreationRequiresWorldGuardBuildPermission: true
    VillagerTradingRequiresPermission: true
    CommandsRequiringAccessTrust: /sethome;/tpahere;
    DeliverManuals: true
    ManualDeliveryDelaySeconds: 30
    RavagersBreakBlocks: true
    FireSpreadsInClaims: false
    FireDamagesInClaims: false
    LecternReadingRequiresAccessTrust: true
  Spam:
    Enabled: true
    LoginCooldownSeconds: 60
    LoginLogoutNotificationsPerMinute: 5
    ChatSlashCommands: /me;/global;/local
    WhisperSlashCommands: /tell;/pm;/r;/whisper;/msg
    WarningMessage: Please reduce your noise level.  Spammers will be muted.
    BanOffenders: true
    BanMessage: Banned for spam.
    AllowedIpAddresses: 1.2.3.4; 5.6.7.8
    DeathMessageCooldownSeconds: 120
    Logout Message Delay In Seconds: 3
  PvP:
    RulesEnabledInWorld:
      world: false
      world_nether: false
      world_the_end: false
      void: true
    ProtectFreshSpawns: false
    PunishLogout: true
    CombatTimeoutSeconds: 15
    AllowCombatItemDrop: false
    BlockedSlashCommands: /home;/vanish;/spawn;/tpa;/back;/sethome;/sell;/ec;/enderchest
    ProtectPlayersInLandClaims:
      PlayerOwnedClaims: true
      AdministrativeClaims: true
      AdministrativeSubdivisions: true
    AllowLavaDumpingNearOtherPlayers:
      PvPWorlds: true
      NonPvPWorlds: false
    AllowFlintAndSteelNearOtherPlayers:
      PvPWorlds: true
      NonPvPWorlds: false
    ProtectPetsOutsideLandClaims: true
  Economy:
    ClaimBlocksMaxBonus: 0
    ClaimBlocksPurchaseCost: 0.0
    ClaimBlocksSellValue: 0.0
  ProtectItemsDroppedOnDeath:
    PvPWorlds: false
    NonPvPWorlds: true
  BlockLandClaimExplosions: true
  BlockSurfaceCreeperExplosions: true
  BlockSurfaceOtherExplosions: true
  LimitSkyTrees: true
  LimitTreeGrowth: false
  PistonMovement: EVERYWHERE_SIMPLE
  PistonExplosionSound: true
  FireSpreads: false
  FireDestroys: false
  AdminsGetWhispers: true
  AdminsGetSignNotifications: false
  VisualizationAntiCheatCompatMode: false
  SmartBan: true
  Mute New Players Using Banned Words: true
  MaxPlayersPerIpAddress: 4
  SilenceBans: true
  Siege:
    Worlds: []
    BreakableBlocks:
    - GRASS_BLOCK
    - DIRT
    - COBBLESTONE
    - OAK_PLANKS
    - SPRUCE_PLANKS
    - BIRCH_PLANKS
    - JUNGLE_PLANKS
    - ACACIA_PLANKS
    - DARK_OAK_PLANKS
    - SAND
    - GRAVEL
    - GLASS
    - GRASS
    - FERN
    - DEAD_BUSH
    - WHITE_WOOL
    - ORANGE_WOOL
    - MAGENTA_WOOL
    - LIGHT_BLUE_WOOL
    - YELLOW_WOOL
    - LIME_WOOL
    - PINK_WOOL
    - GRAY_WOOL
    - LIGHT_GRAY_WOOL
    - CYAN_WOOL
    - PURPLE_WOOL
    - BLUE_WOOL
    - BROWN_WOOL
    - GREEN_WOOL
    - RED_WOOL
    - BLACK_WOOL
    - SNOW
    - GLASS_PANE
    DoorsOpenDelayInSeconds: 300
    CooldownEndInMinutes: 60
  EndermenMoveBlocks: false
  SilverfishBreakBlocks: false
  CreaturesTrampleCrops: false
  RabbitsEatCrops: true
  HardModeZombiesBreakDoors: false
  Database:
    URL: ''
    UserName: ''
    Password: ''
  UseBanCommand: true
  BanCommandPattern: mute %name% 5m Please reduce your spam.
  Advanced:
    fixNegativeClaimblockAmounts: true
    ClaimExpirationCheckRate: 60
    OfflinePlayer_cache_days: 90
  Abridged Logs:
    Days To Keep: 7
    Included Entry Types:
      Social Activity: true
      Suspicious Activity: true
      Administrative Activity: false
      Debug: false
      Muted Chat Messages: false
  ConfigVersion: 1

Plugin list

No response

Running without GriefPrevention

• I attempted running the server without GriefPrevention installed.
• The problem does not occur when GriefPrevention is removed from the server.

Running with only GriefPrevention

• I attempted running only GriefPrevention on the server.
• The issue still occurs when GriefPrevention is the only plugin running.

Running on a fresh, clean server installation

• I attempted testing for the issue on a new server.
• The issue still occurs on a new server.

Using unmodified client

• I attempted testing for the issue with the vanilla client.
• The issue still occurs when using the vanilla client.

We appreciate you taking the time to fill out a bug report!

• I searched for similar issues before submitting this bug report.

[RoboMWM]

chicken eggs or mob spawn eggs?

[TreemanKing]

I believe it is referring to a plugin similar to MobtoEggs (basically the egg is similar to that of a PokeBall) which converts the egg to a spawn egg.

https://github.com/TechFortress/GriefPrevention/blob/de1e72d99353fec63e14a22c377890d406f1de4b/src/main/java/me/ryanhamshire/GriefPrevention/PlayerEventHandler.java#L1392-L1395

Possibly adding a check whether the inventory has been altered or item has been returned might be worth investigating.